Current mobile phone devices do not have the ability to connect to landline or terrestrial-based telephone systems without first traversing the mobile phone network. Similarly, terrestrial-based (e.g., “land-line” or “hard line”) telephones do not have the ability to connect to a mobile phone network. Accordingly, the advantages of mobile phone devices and their accompanying features and service plans may not be used with terrestrial-based telephones, such as prepaid or included long distance, free mobile-to-mobile calling, rollover minutes, etc.